Your Digest for Sunday, Jan 07, 2024 10:59 AM


Broadly, lymphoma is distinguished from leukaemia in its clinical presentation, where lymphoma predominately involves lymph nodes, and leukaemia the blood and bone marrow, and by the fact that lymphomas arise from cells that reside in the lymphatic system rather than in the bone marrow. However, in the context of the cell of origin this is perhaps a rather nebulous distinction, and there is evidence that chronic lymphocytic leukaemia (CLL) may emerge in differentiated/mature lymphocytes in the periphery
[!INFO] The correct identification of AML vs ALL is veryimportant as a determines treatment.

AML ALL
Diverse Group of diseases
Proliferation of myeloid blasts
clonal proliferation of myeloid precursors with a reduced capacity to differentiate into more mature cellular elements.
As a result, there is an accumulation of leukemic blasts or immature forms in the bone marrow, peripheral blood,
Symptoms: pancytopaenic symptoms: anemia, bleeding, and an increased risk of infection. Bone pain is uncommon; Fever = Infection!
Commonest adult acute leukemia (80% of cases) - 65 years Occurs in children.
Accounst for only 10% of paediatric leukemia
About 1.5x commoner in males
Associated with environmental factors
Assoc. with trisomy 21; Fanconi anemia;
Auer rods seen Auer rods never seen.
Myeloblast have finer chromatin and more cytoplasm.
Cells are peroxidase positive.
Lymphoblasts have course chromatin
Cells are PAS positive
negative. Immunophenotyping: Terminal deoxynucleotidyl trasnferase (TdT) positive

Note : T cells are the commonest type of lymphocytes in healthy states, followed by B and NK cells.

  1. Philadelphia chromosome positive

atypicalLymphocytesinMononucleosis.png

EBV / mononucleosis ALL
Teens 4 year olds
Atypical lymphocytes Blast cells
Acute disease course Acute disease course
Splenomegaly and lymphadenopathy hepatosplenomegaly and lymphadenopathy
Lymphocytosis Lymphocytotis with anaemia and thrombocytopaenia
Not present Clinical feature of cell line suppression including mucosal bleeds
Several long term complications: lymphoma, multiple sclerosis, chronic EBV infection, nasopharyngeal CA and others
Very high WBC indicates ALL (but WBC can be low or normal in ALL)